Various speed indicators have been proposed to effectively provide a driver of a vehicle with speed information. These known speed indicators would include various “heads-up” displays, the basic concept of which is to provide the speed indicator display at a position close to the driver's line of sight as the driver looks forward towards the direction of travel, e.g., when the driver of an automobile is looking at the road and traffic in front of a forward moving vehicle. Many of the heads-up displays proposed are directed at applications on automobiles and airplanes.
The operation of snowmobiles, jet skis, ATV's (all terrain vehicles) and motorcycles, in particular, trail bikes, present additional and different conditions for monitoring speed than those presented by automobiles and airplanes. Water and off-road conditions can be expected to vary more rapidly and severely than the conditions of a paved road or the open sky. For example, a fallen tree or boulder may impede the course of a trail bike. A snowmobile may encounter deep powder, ice or a patch of mud, depending upon the place where it is operated, the season, etc. Similarly, partially submerged tree limbs, barrels, rope, etc. may constitute an unexpected obstacle to a jet ski. As a result, it is imperative for operators of off-road vehicles to be highly vigilant for any obstructions or changes in the surface in the path of their vehicle. This vigilance makes it more desirable that the driver look forward at all times, rather than looking down at a speedometer. The degree of surface roughness encountered in off-road travel frequently makes it difficult or impossible for the operator of a jet ski, snowmobile or trail bike to read a speedometer due to the driver's and the vehicle's relative movement. Because off-road vehicles like jet skis, trail bikes and snowmobiles typically do not have closed cabs, weather conditions such as rain, snow, icing, fogging, may also act to reduce or eliminate the driver's capacity to visualize a speedometer. Since the environment in which an off-road vehicle is operated may vary widely, and some environments provide a distorted and/or different perception of speed (e.g., travel over a frozen lake will provide a different sense of the speed of a snowmobile than travel through the wood), operators of off-road vehicles can not rely solely on their innate perception of speed and should utilize an objective measure of speed, such as a speedometer.
The factors of trail difficulty, driver expertise and weather conditions all contribute to ascertaining the speed at which a particular trail may be traveled in safety. If the operator of an off-road vehicle, such as a snowmobile, exceeds a safe speed range for the particular combination of skill level, trail and weather conditions, accidents and injuries can result. Accordingly, an effective system for apprising operators of off-road vehicles of speed related risk associated with operating their vehicle while allowing them to focus on the landscape in front of them is highly desirable.